A group representing mayors of Great Lakes cities in the United States and Canada has dropped its opposition to the City of Waukesha’s switch to a Lake Michigan water supply.

The Great Lakes and St. Lawrence Cities Initiative announced Wednesday that it will not go to federal court to block a diversion of up to an average of 8.2 million gallons a day of lake water to Waukesha.

The eight Great Lakes states in June 2016 unanimously approved Waukesha’s request for lake water.

Waukesha’s plan, when coupled with conditions imposed by the states, complied with a 2008 federal law known as the Great Lakes protection compact, according to representatives of the states’ governors.

The eight states subsequently denied a request by the cities to reverse the ruling.

Rather than suing in federal court, the Cities Initiative said it would meet with representatives of the eight states over the next year to negotiate possible changes to procedures for reviewing future diversion requests.

Among the issues to be discussed: the number of public meetings during the multi-state review process; information on a diversion application to be posted on a publicly accessible website; making amendments to a final decision document; and providing an opportunity for a hearing following a final diversion decision by the states.

“Our challenge has always been about improving the compact to ensure the protection of our water resources,” said Paul Dyster, mayor of Niagara Falls, N.Y., and chairman of the Cities Initiative.

Waukesha Mayor Shawn Reilly applauded the group’s decision not to challenge the project in federal court.

Waukesha will stop using seven deep wells drawing radium-contaminated water from a sandstone aquifer when it switches to a Lake Michigan supply in 2023.

“We will continue to move forward toward providing a sustainable, reliable and safe drinking water supply for the City of Waukesha,” Reilly said.

Absent any other legal challenges, Waukesha will become the first U.S. community located entirely outside the Great Lakes drainage basin to receive a diversion of lake water under terms of the compact.

The compact prohibits Great Lakes water under any circumstances from being pumped beyond counties straddling the lake’s drainage basin. Since Waukesha is located in a county straddling the subcontinental divide between the Great Lakes and Mississippi River drainage basins, it was eligible to apply for a diversion.

The city is planning to build pipelines and pumping stations to bring lake water to the city by 2023.

Waukesha and Oak Creek are continuing to negotiate a final contract for the lakeshore community to sell Lake Michigan water to Waukesha. Milwaukee has stepped in with a last-minute offer to Waukesha in an attempt to wrestle the deal away from Oak Creek.

The 2016 approval of Waukesha’s request requires the city to return an equal amount of the water to the lake as fully treated wastewater. To do that, the city will build a separate wastewater pipeline to the Root River, a lake tributary, in Franklin.